(explosion) >> pelley: tonight, bombs explode at the boston marathon. (screaming) >> run! >> it was horrible, the scene that you saw, it was freaking horrible. >> pelley: there was chaos at the finish line. >> it's so terrifying, it's so scary and there was smoke and glass everywhere. >> pelley: at least two are dead, many dozens hurt. this is the "cbs evening news" with scott pelley. >> pelley: good evening again and for those of you who are just joining us this is a special expanded edition, part of the "cbs evening news" coverage of the terrorist attack today in boston. here is what we know at this hour. two bombs went off near the end of the boston marathon race as runners were making their way to the finish line. what was to be a moment of triumph turned tragic in an instant. at least two people have been killed. more than 50 are being treated

in hospitals, many of them are in critical condition. a third bomb that did not explode was recovered by police. tonight a massive investigation is under way. there has been no credible claim of responsibility and there was no warning. president obama vowed to find and bring to justice whoever is e.sponsible. jonathan elias of our cbs boston station wbz was right there at the scene on boylston street when the attack occurred. jonathan? >> reporter: well, scott, our backs were actually up against the grandstand. it's from behind the grandstand we understand they recovered the device that did not detonate. but if our backs were to the grandstand and literally like right across the street is where the bomb went off it would be the equivalent of -- see these guys walking behind me. that's about the distance where the bomb went off. 30 feet away at the finish line across boylston where the runners were coming across the finish line. perfect day, runners were

ecstatic coming across the line. we were standing there with our photographer and producer and high fiving and celebrating with the runners and in an instant we heard this blast. it rattled us, we saw the smoke come up off the sidewalk. for the first instant everybody stood still not knowing what had just taken place. within a matter of seconds another bomb two blocks up had gone off and at that point everybody knew what was going on. people were running in boylston street, jumping into the street and running past us in each direction. then we ran toward where the bomb had gone off and we were followed by e.m.s. and volunteers from the race and there was a barrier, if you can see this fence here behind me, those fences were all wrapped around boylston to keep the runners separated from the spectators and those fences actually blocked the e.m.s. from getting to the folks on the sidewalk that were hurt. there was t photographer i was working with, brian foley, 6' 5, he grabbed the fence while shooking and yanked the fence back and the scene that we saw on this sidewalk, scott, it's hard to even -- it's hard to get your head around.

i mean, i saw -- in all the carnage there must have been an eight-year-old boy or five-year-old boy sitting upright. he didn't look injured but at his feet was either his mother or father with a leg blown off. their eyes were all open. nobody was crying out and screaming for help, nobody. it was as though everybody was absolutely shell shocked in that moment, completely not coming to grips with what had just happened to them. and all around us there were people with horrific injuries, legs had been blown off, arms had been blown off. people had internal bleeding. there was open wounds. it was horrible. and there was nothing that we could do except pull that fence back to let e.m.s. get in there. but i have to say, had that bomb gone off an hour earlier at the end of the race for the elite runners, they were ten deep in that sidewalk. because it went off in the fourth hour of the third wave you only had maybe three or four deep in that sidewalk. so it was -- there's no silver lining, don't get me wrong, but at the same time there could have been hundreds of people. at last check we know 90 plus people, 98 people are in area

hospitals. as many of those are -- 20 are critical care and two people have been killed and a lot of people are asking who's responsible. scott? >> pelley: that we do not know yet. jonathan elias, thank you from wbz. jonathan was mentioning the people who were wounded. they are now being treated in some of the nation's best hospitals and don daylor is at one of them, massachusetts general hospital. don, what do you know? >> reporter: the doctors are saying had there not been so many first responders at the scene of the tragedy there to care for the runners there probably would have been many more fatalities. as it is, though, the people who were brought to places like massachusetts general in the boston area suffered terrible injuries. the two bombs left scores of injured, the scene reminiscent of a war zone. medical tents set up for the race were quickly transformed into emergency rooms where nurses treated lacerations, broken bones, and severe injuries to legs and feet. >> what really surprised me was

the number of people and just the -- really the amount of blood, the amount of injuries. >> one woman had lost her leg, lots of bleeding. some children were involved as well and we took care of the ones that we could and got them into the ambulance as soon as possible. >> reporter: spectators made makeshift tourniquets to stem the bleeding. this man, one of the on lookers, completely lost his feet. chief of emergency services at massachusetts general alistair khan. some of the patients have already received traumatic amputations at the scene. their legs have been blown off. this is like a bomb explosion that we hear about in the news in baghdad or israel or some other tragic space in the world. >> reporter: and we know of three children at least who were injure including a two-year-old boy who suffered severe head injuries.

scott? >> pelley: don, thank you very much. it's early the investigation. about an hour ago the president briefed the country and said that we do not know who did this, whether it was domestic terrorism or inspired overseas but he said whoever did it would, in his words, feel the full weight of justice. homeland security correspondent bob orr has been talking to his sources all afternoon and, bob, what can you tell us about the investigation so far? >> reporter: scott, at this hour there is no suspect in custody. we are told, though, by officials that there is a young man who they are talking to who quote/unquote could be potentially linked. but it's very, very early on and it's far too strong to say this is a suspect. this is someone who was seen near the site of the blast acting suspiciously and they have to run that to ground to find out if he had any involvement at all. we know there were two devices that exploded. think had been placed in trash cans. there are also two unexploded devices that were recovered near the finish line and that can be very important because those

unexploded bombs and also the remnants of the exploded bombs could provide the kind of forensic evidence that might eventually tell us who put them together, how they were put together and where this attack originated. but right now let's be clear, this is a wide-open investigation field. the suspects range from international terrorists to lone wolfs inspired by international terrorists to perhaps even someone acting on their own on behalf of some kind of domestic cause. it's in the very early stages and officials are running every trap. it's a full-court press to find out how this happened, scott. >> pelley: bob, you were saying to us earlier that there's been no credible claim of responsibility so far. >> that's very important, too. there's been not only no claim of responsibility after the fact, scott, but there was nothing that i'm aware of in the intelligence reporting pipeline in advance of this attack to signal boston was any kind of target today. this really came out of the blue. in fact, to give you an idea of how unexpected it was, it took almost an hour for some of the

federal agents involved to even get to the blast scene. so this was not on anyone's radar which suggests it was either very, very carefully planned or it was a very closely-held plot by maybe one or two people. a lone wolf type plot. >> pelley: bob, thank you very much. another reporter who was at the scene during the explosion was kiley atwood, a cbs news producer. she was on boylston street. kiley, what did you see? >> scott, i was there, i was in between the two bombs. so when the first one went off i was directly to the right of it and we heard a loud explosion, looked around and saw smoke. that's when we knew that something had gone wrong. we heard screaming, yelling, people started running. and i actually ran in the direction of the other bomb. unfortunately ran directly towards that and that's when we started seeing young children being carried by their parents, being carried by police. we also saw some people on the ground. we saw blood all over. it was a really horrific, scary,

scary scene. and right now i'm standing in copley square in boston and this medical tent is where everyone was brought when they were hurt and these people are truly, truly the heroes today because they were the ones who had to deal with everything and we talked to a lot of people who were not physically hurt but mentally devastated and panicked by what they saw. >> pelley: kiley atwood, thank you, kiley. let's orient you a little bit and show you where kylly was when the bombs went off, give you some sense of the proximity of the two explosions. the first bomb was right next to the finish line at the bottom of the screen. the second bomb that went off about 15 seconds later was roughly two blocks up boylston street. the third bomb that did not detonate was also right there by the finish line. senior correspondent john miller is a former deputy director of the f.b.i. he's joining us right now. john, you've been talking to your law enforcement sources all

afternoon. what do you know? >> well, either things are going really well or this is going to be very challenging and that hangs on this individual they have in custody. so let's go back over that. how does this happen? it happens that the first device goes off, the second device goes off and somebody who's noticed this individual saw him acting in a way that they thought was suspicious. they see him running away from the device. now, a reasonable person after an explosion would be rubbing away. but this person had noticed them before. this is a civilian, now. chases him down, tackles him, turns him over to the boston police. the individual who is being looked at was suffering from a burn injury. that means that person was pretty close to wherever this blast went off but not so close as to suffer the serious injuries that other people did. he is in custody. authorities tell me he's being fully cooperative means he's answering all their questions, he's denying any involvement.

i would say they're going to be going over his communications, they'll look into his phone, they'll be getting -- they'll try to look at every aspect of his life and they'll want to talk to that person who found him and tackled him and say what exactly was he doing that was so suspicious. so if that individual pans out that, of course, gives the case a big jump forward. if not, then they're back to physical evidence, forensics, witnesses and whatever they can pick up on those surveillance cameras. >> pelley: these two blocks of boylston street right in the heart of boston are sealed off now as a crime scene. what are they looking for? >> well, what they're looking for is what they can pick up about those two devices that detonated. what set them off? were they command detonated? meaning was somebody standing in between them with a remote control? were they controlled by a cell phone where somebody could have been watching the finish line on television and detonated? or were they carefully timed? and that would be a challenge, scott, to have them timed to go off so close together and to place them in those places without them being detected as

suspicious. >> pelley: what does it mean for the investigation that at least one other bomb was recovered intact? >> that is a big advantage because it is a lot easier to work from a bomb that is intact than it is to piece one togetherring from a million pieces and imagine the parts you can't find. if they have that, if forensic possibilities are almost endless. they could come up with a fingerprint, even one left unintentionally on a piece of duct tape. they could come up with a human hair that matches d.n.a. that they may have taken any number of places so that would be a big break. >> pelley: again at this hour we don't know who did this, we don't know whether it's an act of foreign terrorism or domestic terrorism but the investigation continues, running leads, i suspect, worldwide at this point. john, thank you very much. >> thank you. >> pelley: the bomb attack in boston has the organizers of london's marathon looking at their security because the london race is this sunday. we have more on that from elizabeth palmer.

liz? >> reporter: good evening, scott. both metropolitan police and the london marathon organizers are watching events in boston very closely and hoping for information from u.s. authorities that would indicate whether or not there is now an increased risk of attack here in london. the race is due to go on sunday, more than 37,000 runners have been signed up and, of course, there will be many more thousands of spectators along that 26 miles course. now, the former head of counterterrorism of the metropolitan police told us earlier this evening that even if there is no hard evidence of an increased risk the risk of copy cat attacks will be -- will be assumed to have gone up. so the police will go back over all the intelligence chatter they've had over the last few days very carefully and probably even resurvey the route for what they would consider vulnerable areas in case they have to beef up security in those areas. but bottom line he said really along such a long course there

is there isn't a great deal they can do at this stage to make it 100% safe. >> pelley: elizabeth palmer in our london newsroom. liz, thank you very much. we will update you with the very latest information that we can confirm when we come back in just a moment. i thought, "the red cross does katrina. they don't help single moms. hi. hi. what happened to our house last year? it flooded. and the water flooded out. yeah. the red cross arranged the hotel for us. they gave me that break, that leverage, to be able to get it together and... take care of them, you know? i feel like we've come full circle. like that! this is how i'll do it. sarah: there you go. jamie mcmurray: a boy born in joplin, missouri, was fascinated by anything with wheels and a motor. the odds of him winning both the daytona 500 and the brickyard 400 in the same year? 1 in 195 million.

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know the signs: irritability, excessive urination, weight loss. if you have any of these signs, please call your doctor. early detection can save your life. give to save lives and reach for the cure. call now or log on to childrensdiabetesfoundation.org. 50 wounded in the terrorist attack today in boston. before the boston marathon began there was a impeachment of silence that lasted 26 seconds to honor each of the victims of the sandy hook massacre. and then, a little over four hours later came the bombs at the marathon's finish line. terrell brown is in boston tonight. terrell, what's going on now? >> reporter: scott, you get the sense as you stand here that police still aren't taking any chances. i've been watching and talking to a security guard that's across the street here. by the way, many of the local

businesses along the stretch where we are are closed at this hour. that security guard was told by police to continue checking the trash cans that are nearby at least on this site. he has been pacing up and down the street. one of those trash cans it looks like right now actually being removed across the street. this happening at this very moment. as we take a look here, guys, they have been focusing on these trash cans along this block for some time now. as i mentioned before, police telling security here to look into these trash cans over and over and over again. don't stop. so i've been watching the security guard pace the block here looking at the trash cans along the street. it is these types of measures that are being taken right now. again, as police are telling folks here to just not take any chances, to keep an eye out. the area is sealed off. that's police, that's fire. we've seen state police, we've seen swat teams. we've seen the f.b.i. we've seen u.s. marshals, law enforcement officials here as this is still very much an

active crime scene. we can't see what's happening. we're just on the periphery here. we're about three blocks away from where the initial explosion happened but we've talked to a few witnesses that have described what happened back there, scott, just beyond the perimeter and have talked about it being a very active crime scene even at this hour, scott. >> pelley: terrell brown, thank you very much. boylston street, at least two blocks of it, locked down as a crime scene right in the heart of downtown boston. likely to be locked down for some time as federal agents and local police walk in by inch over that territory looking for any conceivable clue that they might have. it's going to take a while. other cities have stepped up security in light of what happened in boston today. we'll have a look at that next.

you only know, in a fire, to get out, to escape, and now, okay, you're outside and you're safe, but what do you do now? and that's where the red cross came in. we ran out of the house just wearing our pajamas. at that point, just to even have a toothbrush that i could call my own was so important, you know, it just makes you feel like a person again. >> >> pelley: a number of major

cities in the u.s. have increased their security precautions. hundreds of counterterrorism officers have hit the streets in new york city and los angeles is also ramping up its security. bill whitaker is in los angeles for us tonight. bill? >> reporter: scott, police and sheriffs departments are adding extra security to high-profile locations including public transit, government buildings, shopping centers, any place crowds of people might gather. there will be an increased police presence at sporting events, including tonight's dodgers game in los angeles which is a high-profile tribute game to jackie robinson. the stadium will be staffed with additional police officers, bomb squad personnel and bomb-sniffing dogs. commander andrew smith with the l.a.p.d. >> we're looking at our critical sites as we always do in situations such as this but in this case we're looking at the events where there are a large number of people. >> reporter: the sheriff's departments has activated its emergency operations center, a

high-tech command post that consolidate it is city's emergency, police, and fire department. here officials would coordinate any response to mass casualty events. and security has been beefed up at airports along the west coast with more checkpoints, bomb-sniffing dogs and security officers. san francisco police chief greg sur. >> this turns the clock all the way back to 2001 again i think. at least until we find out exactly what happened in boston. so whatever the thinking was on september 12 is now the thinking today. >> reporter: scott, there is no evidence of a threat but until authorities know the nature of those explosions in boston they are take nothing chances. >> pelley: security from coast to coast. bill whitaker in our los angeles newsroom. bill, thank you very much. we're going to be back in just a moment with the very latest on the terrorist attack in boston.

>> pelley: here's what we know at this hour about the terrorist

attack along the route of the boston marathon. two people are confirmed dead, many more than 50 others have been wounded, perhaps as many as 90, and some of them are in critical condition tonight. two bombs went off near the finish line of the marathon today-- which is also patriots' day, commemorating the beginning of the revolutionary war. the blast came 15 seconds apart. less than 100 yards from each other. a third bomb was discovered by police nearby and was disarmed before it exploded. this happened about two hours after the winners crossed the finish line after the crowds had thinned somewhat. we do not yet know whether this is a case of foreign or domestic terrorism but cbs' bob orr has learned that authorities are already questioning someone who was arrested at the scene who was detained at the scene, i should say, and who has been cooperative with police so far. president obama insists that whoever is behind this will,

quote, feel the full weight of justice. much of the heart of boston is shut down tonight. security has been stepped up in major cities from coast to coast. bob orr is joining us in the washington newsroom. bob, is there any reason to believe that this is part of a larger plot? >> as time goes on, scott, officials are getting increasingly comfortable, they're a little nervous but increasingly comfortable that this is not part of some wider plot. they would have expected, they say, to see activities in other cities if something were going to happen. you can't take that to the bank but that is the philosophy they're operating on right now. they're talking to this one person who they've been questioning about a potential involvement in what happened in boston but i have to emphasize this person is not a suspect and i'm told it's way too early even to assume he might be a person of real interest. downtown boston essentially is a crime scene. agents now are going back along the entire route of the marathon looking for shrapnel and evidence as they piece this together, scott.

>> pelley: bob orr, thank you. that is our expanded edition of the "cbs evening news." we are following the breaking news out of the boston marathon where back to back explosions have killed two people and injured dozens more. we have complete coverage of what's happening locally as a result in boston. >> let's get you up to speed. the first bomb exploded near the finish line at about 2 dln:50

this afternoon. two people are dead. there's been conflicting reporte exact number of people injured. that number though could be 100 or more. >> ken joins us live with more from the wusa 9 news room. >> reporter: the number of those hurt continues the rise. there could be up to 100. the window is upwards of 50, maybe as much as 100. whoever carried out this terrorist attack intended for this devastation to be a lot greater. there was at least one other bomb found and detonated by boston police. the information coming out of boston continues to be fluid. everyone across the country, including the president are reacting to the details we have right now. >> i've directed the full resources of the federal government to protect people, increase the security around the united states and investigate what happened. >> president obama addressed the nation today, saying over federal resource needed is being deployed to boston as the

numbers of those injured and killed rise. he said investigators are working to find out who is responsible for this and why they did it. >> boston is a tough and resilient town, so are its people. they will pull together and take care of each other and move forward. >> the first blast happened at 2:50 right at the finish line. seconds later a second explosion about a block away. a fire originally thought to be the result of a third blast has been confirmed to have been a mechanical fire at a library, not a third bombing. however, a boston bomb squad did detonate we're other device they believe was intended to explode. >> there was a big fire ball. everybody went into panic mode, started running down the finish line towards the common. >> at least two are confirmed dead. the number of those injured